Actuators, such as solenoids, pumps, valve assemblies, servo motors, or relays, may be used in various vehicle systems such as in propulsion systems, emissions systems, air management systems, or other vehicle systems for operating devices, such as clutches, brakes or valves. In a propulsion system, a solenoid may engage or disengage a gear or a clutch. In an emissions system, a solenoid may regulate exhaust gas entering an intake manifold. In an air management system, a valve assembly may divert airflow and/or vacuum. In the control of such vehicle systems, electric power may be provided to an actuator through a power module having high and low side drivers. High and low side drivers may be solid-state switches such as metal-oxide semiconductor field-effect transistors (MOSFETs). Regardless of the particular switch technology used, in the high side driver, the switch allows a current to flow from a power supply (high potential) to an actuator. In the low side driver, the switch allows a current to flow from the actuator to a low potential, such as ground.
In some power modules, the high side driver has a current rating sufficient to power multiple actuators. Typically, multiple actuators are connected to one high side driver until it reaches capacity (generally due to the current draw of the actuators). Then another high side driver is added to the power module until all necessary actuators are connected through a high side driver. Each actuator is also connected to a separate low side driver. When a fault occurs in an actuator, connected low side driver, or an associated device (referred to generally as a failed component) in such a vehicle system, an algorithm in the power module or other controller generally sends a separate command to each of the low side drivers connected to the other actuators to turn on or off individually so as to minimize the impact of the failed component on vehicle operation. Since there are multiple actuators, low side drivers, and devices in each vehicle system, many control commands may be required to put a vehicle in a desired operational mode while isolating the failed component, leading to slow and complex fault mitigation systems.